Raster images

You can place raster images (photos, orthophotos, scanned drawings, logos) in the drawing, as in AutoCAD: the drawing stores only the image path, its position, size and rotation, not the pixels. So the image file must always travel with the drawing.

Formats

PNG, JPEG, BMP, TIFF (including GeoTIFF and tiled TIFF), GIF and WebP. ECW, MrSID and JPEG 2000 cannot be read (the Spanish PNOA orthophotos come as ECW): when a drawing that attaches them is opened you are warned, their frame says Unsupported format, and CONVERTIMAGE converts them to GeoTIFF with GDAL (QGIS or OSGeo4W, installed separately) and attaches the result in the same place. The original is not deleted.

Inserting an image

Enter IMAGEATTACH or use the Insert tab. Enter opens the dialog box to choose the file.
Specify the insertion point (lower-left corner). The Path option chooses whether the path is saved Relative to the drawing folder or Full.
Enter the scale factor (with 1, the image takes the size given by its resolution and the drawing units) and the rotation.

To place an image at its real-world coordinates, use GEOIMAGE or GEOREFIMAGE (see Geolocation).

Managing the images of a drawing

The XREF window lists the images with their status, size and coordinate system, and has buttons to Reload, Detach and Change Path…; those in an unsupported format also have Convert with GDAL… (in the row and in its shortcut menu).
-IMAGE does the same on the command line: ? lists them; Detach, Path, Reload and Unload ask for the image name (* for all); Attach attaches a new one.
If an image is not found when the drawing is opened, its frame is shown with the file name; change the path to see it again.

Adjusting the image

Command	What it does
IMAGECLIP	Shows only part of the image, inside (or outside, with Invert) a rectangular or polygonal boundary
IMAGEADJUST	Changes brightness, contrast and fade (0 to 100)
TRANSPARENCY	Lets what is underneath show through the transparent pixels of the file
DRAWORDER	Brings the image below or above other objects

The IMAGEFRAME variable controls image frames: 0, no frame; 1, displayed and plotted; 2, displayed but not plotted (for now LinceCAD plots it too).

An image is moved, copied, rotated and scaled like any other object.

Large images

Very large images (orthophotos of hundreds of megapixels) are loaded in tiles and in the background: a reduced version appears first and the detail arrives as you zoom in. Their memory use is capped, so you can work with several at once. Huge PNG and JPEG files, unlike TIFF, are read whole; it is better to convert them to TIFF.

Plotting

Images come out in PDF, SVG and PNG with their clipping and transparency. To keep files from growing without limit, each image is plotted at 300 dpi and 16 megapixels at most.

Notes

Images are saved in DWG and DXF as AutoCAD saves them, and AutoCAD opens them in place.
Brightness and contrast are close to, but not exactly, AutoCAD's.